The present invention relates to worklights and is more particularly directed to switch arrangements for turning the worklight on and off.
Worklights have become popular for use in such varied settings as construction jobs, industrial plants, automotive and auto body repair shops, artist and photographic studios, and projects around the home. A typical worklight has one or two, or sometimes more, worklight heads that are supported on a base, which may be set on the floor or other work surface, mounted on a tripod, hung from a hook or mounted on a clamp that is in turn clamped to a supporting structure in the work area. Halogen worklights have become popular because they provide a lot of light, but they also generate a lot of heat, too. The lights are typically turned on by a push-button switch that is mounted on the back of the worklight head. Some worklight heads are capable of several light levels. For example, the head may include two halogen lamps and the user actuates the light by consecutively pushing on a push-button switch to energize, in sequence, a single lamp, both lamps and neither lamp.
FIG. 1 shows a rear view of a halogen worklight of the prior art with a conventional switch arrangement. The worklight includes a worklight head 10 mounted on a base 11 that rests on the ground or other work surface during use. The illustrated head may be tilted with respect to the base to aim it in a desired direction by grasping handle 12 and pressing tilt-release lever 13 to adjust the angle of the head. The head includes a worklight body 14, the exterior of which is seen in FIG. 1, which houses one or more halogen lamps. Electrical connections are made to the lamps through switch box 16. Power is provided to the switch box through power cord 17. During operation the halogen lamps generate quite a bit of heat, and cooling fins 18 and 19 are provided on the worklight body to help dissipate the heat. Nevertheless, halogen worklights are known to get very hot during use.
The switch box is generally located at the rear of the worklight head, typically attached at the lower portion of the head as illustrated in FIG. 1. The halogen lamps are controlled by a push-button switch assembly 20 mounted on the switch box. The switch has a plunger in the form of a shaft that extends out of the box and is covered by a flexible plastic protective covering 21 or boot, as it is commonly called, to guard against dust and moisture from impairing the switch action or electrical connections. The plastic boot is held in place by screw ferrule 22, which screws onto the switch body. The switch is actuated by pushing on the top of the boot.
Although conventional, the use of such a switch arrangement is inconvenient at best and, more precisely, just plain awkward. The switch is not located in a very accessible position, and the switch mechanism can be fairly stiff. Users typically actuate the switch in one of several ways. In one approach the user grasps the switch and switch box between the thumb and one or two fingers, with the thumb on the top of the boot and the one or two fingers on the back of the switch box, and squeezes until the switch clicks. To achieve this, the user either leans over the worklight or stands to the side of or behind the worklight to gain sufficient access to locate the switch and orient the thumb and fingers properly, while guarding against contact with the hot surface of the worklight body. In another approach the user stands, kneels or bends so that the switch is visible and then simply pushes on the top of the boot with one finger—typically the index finger. This tends to hyperextend the distal interphalangeal joint causing discomfort at the least and for some users contributing to other future joint injury or repetitive stress injury. In any case the user sometimes has to stabilize the worklight by grasping the handle or base with the otherwise free hand so that the light does not slide when the switch is pushed.
Mounted on the back side of the housing, the switch box is typically out of the direct view of the user working in front of the light. The particularly bright light from a halogen worklight can also diminish, if not obscure altogether, the user's vision while reaching to shut off the light or change the light level. For a halogen lamp that has been operating for awhile, the exterior walls of the worklight head will become too hot for human touch, making it more difficult and potentially hazardous for an inattentive or less-than-careful user to reach around behind the light to turn it off. Moreover, finding and pushing the conventional push-button switch is made even more troublesome to the worker with a gloved hand. In addition to the problems of actuating the switch, the plastic boot 21 tends to deteriorate and crack with age, which effectively defeats the purpose of the boot. The plastic material tends to slide and rub against the end of the switch shaft every time the user pushes on the switch, leading to premature demise of the boot, which effectively limits the useful life of the worklight. The tendency of the plastic boot to slide or give under the user's finger when pressing the switch also makes for a mushy or spongy feel that is less than comfortable.
Notwithstanding the many inconveniences and deficiencies of the conventional worklight switch arrangement, the switch arrangement has nevertheless become the generally accepted standard. Over the years users have grown accustomed to these inconveniences and deficiencies, learned to tolerate them, and have come to accept them as inevitable and unavoidable.